Bulk Image Resizer

Resize hundreds of images at once by pixels or percentage. Fit, fill or stretch modes, keep aspect ratio, download all as ZIP. No upload, free.

Your images never leave your browser

BulkZIP downloadNo upload

Loading tool…

How to use the Bulk Image Resizer

1Drop up to 200 images into the upload zone.
2Choose Pixels (width and/or height) or Percentage scaling.
3Pick a fit mode: fit, pad, fill or stretch; keep "Maintain aspect ratio" and "Don't enlarge" on unless you need otherwise.
4Select the output format (JPG, PNG or WebP) and download all as a ZIP.

Resize hundreds of product photos in one go

Supplier catalogues arrive as 4000×4000 JPEGs, phone shoots arrive as 4:3 rectangles, and your theme wants 1200 px squares. Doing that one image at a time in a desktop editor is an afternoon lost. The Bulk Image Resizer is a batch resize images tool that takes up to 200 files, applies one rule to all of them and hands back a ZIP.

How it works

Drop the images into the upload zone. JPG, PNG, WebP, BMP, GIF and iPhone HEIC are all decoded in the browser.
Choose Pixels and type a width, a height or both, or choose Percentage to scale everything by the same factor, for example 50%.
Pick a fit mode, keep Maintain aspect ratio on unless you deliberately want distortion, and leave Don't enlarge on so small images are never blown up.
Choose JPG, PNG or WebP and a quality level, then download.

Fit mode	What it does	Best for
Fit	Scales to fit inside the box, keeps ratio, no padding	Thumbnails, email images
Pad	Fits inside the box and fills the rest with a colour	Square product grids
Fill	Scales to cover the box and centre-crops	Banners, uniform galleries
Stretch	Forces the exact size, ignores ratio	Rare; only when distortion is acceptable

Resizing runs in a pool of Web Workers so a batch of 100 images finishes in seconds, and changing any option re-runs the batch automatically.

Why it matters

Pixel dimensions drive both compliance and page speed. Every marketplace publishes a ceiling: Shopify accepts up to 4472×4472, eBay up to 9000 px, Amazon up to 10,000 px and Daraz only up to 3000×3000. Upload beyond those and the file is rejected outright. Below the floor, zoom disappears: Amazon needs at least 1000 px, Etsy 2000 px on the shortest side, eBay 500 px and TikTok Shop 600 px.

Size also decides how heavy your storefront is. A 4000×4000 JPEG is typically 3–5 MB; the same photo at 1200×1200 is around 200–300 KB. Shopify caches resized copies for you, but a custom theme, a WordPress store or an email campaign does not, so resize image by percentage or to an exact width before you publish.

Tips

Percentage mode is the fastest way to halve a folder: 50% halves both sides and cuts the pixel count to a quarter.
Set only the width when photos are mixed portrait and landscape; height follows the aspect ratio and nothing is cropped.
Use Fill for a uniform thumbnail grid and Pad with white for square marketplace tiles. If you need per-image framing, the Image Cropper gives you a manual crop box.
For marketplace-specific sizes, the Marketplace Preset Resizer already knows the Amazon, Shopify, Etsy, eBay, Daraz and TikTok Shop numbers.
Resizing reduces file size, but to hit a byte target such as under 500 KB, run the output through the Bulk Image Compressor. Converting HEIC or WebP for a picky uploader is the job of the Image Format Converter.

Privacy

This bulk image resizer is entirely client-side. Your images never leave your browser: they are decoded, scaled and re-encoded on your own device and the ZIP is built locally. No uploads, no server queue, no file retention. See the Shopify image size guide and the eBay picture requirements for each platform's full numbers.

Frequently asked questions

What is the difference between "Fit" and "Fill"?

Fit scales the image so it sits entirely inside your width and height with no cropping, so the output can be smaller than the box in one direction. Fill scales until the box is covered and trims the overflow, giving you the exact size every time at the cost of the edges.

Can I resize only by width and let height follow?

Yes. Enter a width, leave height blank and keep "Maintain aspect ratio" on. A 4000×3000 photo becomes 1200×900, a portrait 3000×4000 becomes 1200×1600, and nothing is cropped. This is ideal for mixed-orientation catalogues.

What does "Don't enlarge" do?

It skips any image already smaller than the target so it is not upscaled into a blurry version. A 900 px image stays 900 px. Turn it off only when a marketplace minimum-size check matters more than sharpness.

How many images can I resize at once?

Up to 200 per batch, limited mainly by the memory of your device. Images are processed a few at a time in Web Workers, so a laptop handles 100 phone photos in well under a minute. For larger catalogues, run several batches.

Which output format should I choose?

JPG for photographs going to marketplaces. PNG when you need transparency or crisp graphics. WebP when the images are for your own website, since it is roughly 25–35% smaller than JPG at the same visual quality, though Amazon, Etsy and eBay do not accept it.